Trump administration threatens to step up pressure against Iran and Venezuela in run-up to 2020 election

US officials have warned they will dramatically step up global pressure on Iran in the coming days by imposing sanctions to block weapons and energy shipments to Tehran.

Such a move raises the possibility of American warships halting Iranian cargo ships in international waters, which would be a further escalation of tensions between the two countries, in the run-up to the most contentious US presidential election in recent history.

The hawkish US envoy to Iran and Venezuela Elliott Abrams said that Washington would spell out measures in the coming days it would take to enforce sanctions against the Islamic Republic – as well as similar measures against Caracas, where the US supports the opposition against the regime of Nicolas Maduro – an ally of Tehran.

The added pressure would be in contravention of a United Nations Security Council’s decision to reject the US attempt to reimpose brutal sanctions on Iran that were removed as part of the 2015 Joint Comprehensive Plan of Action, the nuclear accord.  

The administration of Donald Trump has only a few months left in its first and possibly last term. But the US may see any move against long-standing foe Iran as a potentially popular move with some voters.  

Mr Abrams, who recently took over Iran policy from the departing Brian Hook, is known for his foreign policy adventurism. He was once convicted for his part in a scheme to use proceeds of illegal arms sales to Iran to finance Central American militias accused of war crimes. He was later pardoned.

Some fear enforcement of the sanctions could entail US warships halting Iranian or Iranian-bound cargo ships in international waters.

“Will they try to stop ships in the open waters that are trying to bring non-military goods? That’s a very good question,” said one senior European diplomat. “If the US tried to stop a shipment to Iran, I don’t know what ensues. It will create another element of uncertainty in an already uncertain situation.”

The US already seized several Iranian tankers bound for Venezuela with cargoes of fuel but in open waters far from the Iranian military.

“If the Trump administration starts targeting Iranian vessels in the Persian Gulf or near the Strait of Hormuz, the risk of a confrontation with Iranian naval forces will significantly increase,” Trita Parsi, of the left-leaning think tank Responsible Statecraft, wrote on Wednesday.

Many officials have questioned the Trump administration’s legal reasoning for tightening sanctions. Under its interpretation, all the harsh UN sanctions in place on Iran before the 2015 nuclear deal are to come back into force because Washington demands an immediate “snapback”.

“Virtually all UN sanctions on Iran will come back into place this weekend at 8.00pm Eastern Time on Saturday the 19th,” Mr Abrams told reporters late Wednesday. “The arms embargo will now be re-imposed indefinitely and other restrictions will return.”

Mr Abrams was speaking hours after US secretary of state Mike Pompeo, speaking alongside British foreign secretary Dominic Raab, said the US would do “all the things we need to do” to reimpose or snapback sanctions as part of a provision in the nuclear deal.

Those restrictions include limits on Iran’s missile development and  enrichment of uranium,  which remain under international safeguards, despite Washington withdrawing from an international agreement to monitor Iran’s nuclear programme in 2018. So far, Tehran has only enriched uranium to power reactor levels. Iran has warned that any reimposition of the pre-2015 sanctions would have dire consequences.

Other countries involved in the nuclear deal, the UK, France, China, Germany and Russia, contend that the US cannot trigger the snapback because it has withdrawn from the deal.

On Thursday the hardline Iranian daily newspaper Javan warned: "If Europe does not officially and practically cancel the snapback mechanism on Saturday, it will see the end” of the nuclear deal.  

“Iran should turn off the cameras and start 90 per cent enrichment,” the newspaper said.

Uranium enriched to 90 per cent purity is considered weapons grade.

As a possible response to Iran, Mr Abrams mentioned increased sanctions on Iran or any entity that does business with the country. But at this point, it remains unclear if any more sanctions will have any effect.

“There will always be more sanctions and companies to target,” said Sanam Vakil, an Iran and Middle East expert at Chatham House. “But the impact is negligible at this point.”

The US approach has puzzled and alarmed Nato partners that are struggling to maintain limits on Iran’s nuclear programme without resorting to armed conflict, a stated goal of the Trump administration.

Some observers have wondered if the Trump administration is merely trying to appear tough on Iran in order to sate the appetite of Republican Party financiers and think-tank cheerleaders increasingly frustrated with their inability to topple the regimes in Tehran as well as Caracas.

Other observers and diplomats worry that the Trump administration hopes to provoke a crisis before the 3 November elections, in which Democratic Party challenger Joe Biden has an advantage in the polls.

“They’ve been mentioning snapback for months; it would have been a surprise if they hadn’t tried to pursue it,”  said the senior European diplomat. “What’s unclear is if it's for domestic political calculations or how they're going to pursue it. Are they going to make a speech and go home or are they going to stake to stop ships?”

While Mr Trump has often described himself as the president who would end America’s wars abroad, his calculations may change if he decides a military clash with a longtime adversary would help rally voters behind him.

“There is awareness among the [Security Council] and the policymaking community that in the run-up to the elections it could be useful to continue to demonstrate toughness with Iran to potentially achieve the aim of killing the [nuclear deal],” said Ms Vakil. “But I don't see the wider international community as enablers. They’re quite clear-eyed that they are not going to be goaded.”